Spintronic Device Comprising Dual FGL and Dual SPL To Reduce Perpendicular Field At Writing Location

Abstract

The present disclosure is generally related to a magnetic recording device comprising a magnetic recording head. The magnetic recording head comprises a main pole, a hot seed layer, and a spintronic device disposed between the main pole and the hot seed layer. The spintronic device comprises two field generation layers (FGLs), two spin polarization layers (SPLs), and two spin kill layers. The second SPL of the spintronic device drives the second FGL. The spintronic device further comprises one or more optional thin negative beta material layers, such as layers comprising FeCr, disposed in contact with at least one of the spin kill layers. When electric current is applied, the spin kill layers and optional negative beta material layers eliminate or reduce any spin torque between the FGLs and the SPLs.

What is claimed is: 
     
         1 . A magnetic recording head comprising:
 a shield;   a main pole; and   a spintronic device disposed between the shield and the main pole, the spintronic device comprising:
 a first spin kill layer; 
 a first spin polarization layer; 
 a first field generation layer; 
 a first negative beta material layer; 
 a second spin kill layer; 
 a second spin polarization layer; and 
 a second field generation layer, 
 wherein the second field generation layer is disposed over the main pole, the second spin polarization layer is disposed over the second field generation layer, the second spin kill layer is disposed over the second spin polarization layer, the first negative beta material layer is disposed in contact with the second spin kill layer, the first field generation layer is disposed over the first negative beta material layer, the first spin polarization layer is disposed over the first field generation layer, and the first spin kill layer is disposed over the first spin polarization layer. 
   
     
     
         2 . The magnetic recording head of  claim 1 , wherein the spintronic device further comprises a second negative beta material layer disposed between and in contact with the second spin polarization layer and the second spin kill layer. 
     
     
         3 . The magnetic recording head of  claim 2 , wherein the spintronic device further comprises a third negative beta material layer disposed in contact with the first spin kill layer. 
     
     
         4 . The magnetic recording head of  claim 3 , wherein the spintronic device further comprises a fourth negative beta material layer disposed between the first spin kill layer and the first spin polarization layer. 
     
     
         5 . The magnetic recording head of  claim 4 , wherein the first, second, third, and fourth negative beta material layers each individually comprises FeCr and has a thickness of about 1 nm. 
     
     
         6 . The magnetic recording head of  claim 1 , wherein the spintronic device further comprises:
 a first spacer layer disposed between and in contact with the first spin polarization layer and the first field generation layer;   a second spacer layer disposed between and in contact with the second field generation layer and the second spin polarization layer; and   a third spacer layer disposed between the second field generation layer and the main pole.   
     
     
         7 . The magnetic recording head of  claim 1 , wherein the first and second spin kill layers each comprises a non-magnetic material having a resistivity greater than about 100 nano-Ohm·m. 
     
     
         8 . A magnetic recording device comprising the magnetic recording head of  claim 1 , the magnetic recording device configured to flow a current from the shield through the spintronic device to the main pole. 
     
     
         9 . A magnetic recording head comprising:
 a shield;   a main pole; and   a spintronic device disposed between the shield and the main pole, the spintronic device comprising:
 a first field generation layer disposed adjacent to the main pole; 
 a first spin polarization layer disposed over the first field generation layer; 
 a first spin kill layer disposed over the first spin polarization layer; 
 a second field generation layer disposed over the first spin kill layer; 
 a second spin polarization layer disposed over the second field generation layer; 
 a second spin kill layer disposed between the second spin polarization layer and the shield; and 
 one or more negative beta material layers disposed between the main pole and the shield. 
   
     
     
         10 . The magnetic recording head of  claim 9 , wherein the second spin kill layer is disposed in contact with the shield. 
     
     
         11 . The magnetic recording head of  claim 9 , wherein the second spin kill layer is disposed in contact with the second spin polarization layer. 
     
     
         12 . The magnetic recording head of  claim 9 , wherein a first negative beta material layer of the one or more negative beta material layers is disposed between the first spin kill layer and the second field generation layer. 
     
     
         13 . The magnetic recording head of  claim 9 , wherein each of the one or more negative beta material layers is disposed in contact with either the first spin kill layer or the second spin kill layer. 
     
     
         14 . A magnetic recording device comprising the magnetic recording head of  claim 1 , the magnetic recording device configured to flow a current from the shield through the spintronic device to the main pole. 
     
     
         15 . A magnetic recording device, comprising
 a magnetic recording head, the magnetic recording head comprising:
 a shield; 
 a main pole; and 
 a spintronic device disposed between the shield and the main pole, the spintronic device comprising:
 a first field generation layer disposed adjacent to the main pole; 
 a first spin polarization layer disposed over the first field generation layer; 
 a first spin kill layer disposed over the first spin polarization layer; 
 a second field generation layer disposed over the first spin kill layer; 
 a second spin polarization layer disposed over the second field generation layer; 
 a second spin kill layer disposed between the second spin polarization layer and the shield; and 
 one or more negative beta material layers disposed between the first spin polarization layer and the shield; and 
 
 means for flowing a current from the shield through the spintronic device to the main pole. 
   
     
     
         16 . The magnetic recording device of  claim 15 , wherein the first and second spin kill layers each comprises a non-magnetic material having a resistivity greater than about 100 nano-Ohm·m. 
     
     
         17 . The magnetic recording device of  claim 15 , wherein each of the one or more negative beta material layers is disposed in contact with either the first spin kill layer or the second spin kill layer. 
     
     
         18 . The magnetic recording device of  claim 15 , wherein a first negative beta material layer of the one or more negative beta material layers is disposed between the first spin kill layer and the second field generation layer, and wherein a second negative beta material layer of the one or more negative beta material layers is disposed between the first spin kill layer and the first spin polarization layer. 
     
     
         19 . The magnetic recording device of  claim 18 , wherein a third negative beta material layer of the one or more negative beta material layers is disposed between the second spin kill layer and the shield, and wherein a fourth negative beta material layer of the one or more negative beta material layers is disposed between the second spin kill layer and the second spin polarization layer. 
     
     
         20 . The magnetic recording device of  claim 15 , wherein the one or more negative beta material layers each individually comprises FeCr and has a thickness of about 1 nm.